My Kenmore Central Vac loses suction

Question

Hi My Kenmore Central Vac loses suction while vacuuming, it will be doing fine... then loses it for a few seconds, then back on. If I twist the connect at the wall base the suction stays on the whole time (but then it's not lined up), I've never thought it worked well. (I've been in the house for 5 years and the unit is about 10 years old) I don't want to pay a repair guy to come out just to tell me I need to buy a new part.... is there any ideas or solutions?